PYB110 Lecture Notes - Lecture 2: Standard Deviation, Unimodality, Central Tendency

• School: QUT
• Department: Psychology and Counselling
• Course: PYB110
• Professor: Rhys Luckey

Document Summary

Mean: average, method: su(cid:373) of all s(cid:272)o(cid:396)es divided (cid:271)y (cid:858)n(cid:859) (cid:374)u(cid:373)(cid:271)e(cid:396) of s(cid:272)o(cid:396)es, represent all scores (data set) because influenced by all scores in the distribution. Symbols (mean: m = mean, = (cid:858)the su(cid:373) of(cid:859, x = score in the distribution of variable x, n = number of scores in a distribution (cid:1839)= (cid:1840) Median: the most common occurring score in a unimodal distribution, the peak of a histogram or frequency polygon. In symmetrical unimodal distribution (aka normal distribution): mode = mean: the middle score when scores are ranked. If odd number of scores, median is middle score. Mode: when number of values/ categories are few. Median: when shape of distribution is skewed. Mean: when shape of distribution is not skewed: normal distribution: mean = median = mode. Variability: how spread out the scores are in a distribution. Range: difference between the highest & lowest obtained scores, range = highest score lowest score.